Brake



Oct. 3, 1944. F FRANK 2,359,516

BRAKE Filed Sept. 1B, 1940 5 Sheets-Sheet 1 Z6 1*2 l r /5 .Humm

TTORNE Y Oct. 3, 1944. I F. c. FRANK BRAKE Filed sept. 1s, 1940 5 Sheets-Sheet 2 X INVENTOR 5 B fREOE/P/CKC. FPA/VK A-TTQRNEY Oct. 3, 1944. F, Q FRANK 2,359,515

BRAKE Filed sept. 18, 1940 I 5 sheets-sheet 4` IN VEN TOR A TTORNE Y Oct. 3, 1944. F. C, FRANK 2,359,516

BRAKE i Filed Sept. 18, 1940 5 Sheets-Sheet 5 A TTC-RNE Y Patented Oct. 3,1944

v2,359,516v 'd BRAKE Frederick C. Frank,l South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation oi' Delaware Application September 18, 1940, Serial No. 357,209 4 claims. (ol. iss-152) 'I'he present invention relates to uid pressure brakes and is illustrated as it might be used in conjunction with disc brakes for aircraft.

A primary object of the invention is to provide v an improved pressure transmitting member for moving the stator portion or portions of the brake against the rotor portions thereof. To this end I have furnished a distensible rubber capsule, one side of which is confined in a recess in the brake applying piston, and the opposite side of which is confined within the Walls of an annular chamber in which the piston moves. This serves to prevent any scrubbing action on the cylinder wall which might abrade the distensible or expansible capsule. The confinement of the tube or capsule also tends to eliminate any danger of bursting the tube, inasmuch as there is always support for the tube at the places where the braking pressure is transmitted. It will be ob-l vious that my invention will accomplish the purposes set forth under this rst objective in any type of brake whether it be a disc or a drum brake and whether it be applicable to land vehicles or aircraft.

A further object of my invention is to provide novel and eiective means for cooling the friction members. of the brake. Briefly this will be accomplished by drawing air past the rotor portions of the brake in a steady uni-directional stream.

Another object of my improved brake is to provide means for adjusting the brake to compensate for the wear of the friction lining and to accomplish such adjustment without removing the brake or the wheel with which it is associated from the airplane or other vehicle to which it is attached. This object is accomplished by making the cylinder portion of the brake applying means adjustabley on the brake spider or supporting plate.

@ther objects and desirable features of my invention will become apparent during the course of the ensuing description wherein reference will be had to the accompanying drawings, in which:

Figure 6 is a section taken on the line 6-6 of Figure 5;

Flgure-7 is a section taken on the line 1-1 of Figure 5; A

Figure 8 is a section taken on the line 8-8 of Figure 5; and

Figure 9 is asection taken on the line 9--9y of Figure 5.

In Figures 1 to i inclusive I have shown a wheel and brake assembly which includes a rotatable portion comprising a wheel I0 and an annular disc or rotor brake member II; and a non-rotatable portion comprising a supporting member or backing plate I2, an annular chamber forming or enclosing member or cylinder I3 nxed to the supporting member and an annular plunger or piston member I5 which serves as the stator portion of the brake. As seen most clearly in Figure `3 the periphery of the annular disc or rotor brake member II is splined to the wheel I0. This allows the disc II to move axially of the wheel II) but prevents circumferential movement of the disc.

The supporting member or backing plate I2 has an annular flange I6 which is faced with brake lining Il of any suitable or desired type.

'The face of the plunger or piston member I5 and I8 out of engagement with the disc II until the brakes are intended to be actuated.

The piston member I5 is reclprocable in an annular chamber or recess 2G formed in the member I3. Between the wall of the chamber 2li and the piston I5 is placed an extensible tube 2l made of rubber or other resilient material. A recess 22 is formed in the side of the piston adjacent the tube 2l. One end of the tube 2| is confined within the recess 22 of the piston and the opposite end of the tube 2| is confined Within the walls of the chamber 20. The side walls ofthe tube are folded inwardly, i. e., toward the center thereof as shown at 29.

In order to provide a strong and substantial tube, capable of withstanding heavy strains and stresses, I have formed a tube with one or more pieces of fabric in the center of the rubber body of the tube (Figure 4). The use of the fabric as a base or support for the rubber or other resilient material used in the tube serves to provide an exceptionally strong tube while at the same time permitting the rubber to adequately seal the fluid admitted to the interior of the tube.

As shown at 23 an opening is provided in the tube 2l. Adjacent the opening is .a recess 24 formed in the element I3. An externally threaded bolt 25 extends into the recess 24 and is threadedly engaged by a washer nut 26 which is -arranged to clamp the tube against the walls of the chamber 20 adjacent the aforesaid opening in the tube. Sealing of the tube is thus accomplished through coaction of the bolt 25 and the washer nut 26. A series of passages through the washer 26, the bolt 25, and the member |3 conmember I5 in the direction of the ange I6 to" cause frictional engagement between the parts I1 and I8 and the disc II, the friction created impeding the rotation of the wheel l0. It will be noted that the sides of the expansible tube 2| do not rub along the walls of the chamber 20 face of vthe flange IIB. The provision of this extra friction surface adds available braking surface and allows the body of the wheel to support the backing plate and its ange when the said flange is pushed to the right owing to the stress of excessive force applied during brake application.

The brake actuating expansible tube |2l and the brake applying annular piston llli are substantially similar to the tube and piston shown Y in Figures 1 -to 4. The annular chamber forming member I|3 is, however, so formed and secured in the brake assembly as to be adjustable. It will be noted that the chamber forming or enclosing member I|3 is threaded as at |I3b and 'is screwed onto an outwardly extending flange l|2a of the backing plate member II2. A holding device |34 is associated with the flange |l2a and the annular chamber forming member |l3 to prevent unwanted rotation of the member -l I3. When there has been considerable wear on the several friction surfaces of the brake the play or slack in the brake may be considerable. If it is then desired to adjust the brake this may be accomplished by temporarily releasing the holding device I 34, making one or more complete turns of during application of the brakes, the expansion that shown in Figures 1 to 4. I'here are, however, features of the modified device which make it worthy of mention in this specification.

Because of the general similarity in the two forms of my brake I shall use in Figures 5 to 9 the same designating numerals as used in Figures 1 to 4 with the addition of |00. It will be seen that the modified device includes a plurality of annular discs lll, Illa, and lllb which are secured to a wheel |l0 and are rotatable therewith. A friction lining II1 is riveted or otherwise attached to an annular flange I|6 extending from a supporting member or backing plate ||2. A friction lining ll8 is secured to the face of an annular contact member Ilia which cooperates with a piston yl l5 in moving the stator and rotor brake elements into frictional engagement with one another.` Between the rotor discs Ill and Illa, and between the discs Illa and lllb are stator discs Ita and lI6b, each having a pair of friction surfaces, the four friction surfaces thus formed being designated by the numerals Il'la, Il'lb, II'lc, and II1d. 'I'he stator,.discs are keyed to the non-rotatable brake supporting member ||2 by means of locking elements |31 which prevent rotation of the stator discs while allowing them to be moved along the axis of the wheel. It will of coursebe appreciated that any suitable or desirable number of rotor discs, stator discs, and associated friction surfaces may be provided. f

A novel feature of my brake as shown in this modification is the use of an annular friction plate |30 which is fastened by suitable means, as bolts |3I to the body of a wheel |32.v A friction material |33 is secured on the wheelward the annular member II3 and again locking the member Il3 by means of the device |34. This turning of the member ll3 will cause that member to move to the right or in the direction of the Wheel body. 'I'he member ||3 will thus push the annular contact member lia and through it move the stator and rotor discs into closer relationship with one another. In this connection it would be noted that the outer surfaces of the rotor discs Il l, I la and Illb are furnished with channels |35 which accommodate keys |36, the effect of the keys being to allow adjusting movement of the rotor discs along the axis oi' the wheel and drum while causing the rotor discs to rotate with the wheel and drum.

An advantageous feature of my device is the cooling means provided for the brake. Referring to Figure 5, it will be noted that a series of openings or inlets |30 are provided in the supporting member |32. Air from the center of the brake assembly may thus be drawn from a chamber |39 formed between the brake drum and the brake supporting member, through the air inlets |38 and into contact with the friction parts of the brake. In Figure 8 it will beapparent that the brake lining or friction material with which the stator brake elements are faced is segmented to provide spaces |40 between.v

the separate pieces of brake lining. Thus the centrifugal force of the rotating drum and rotor discs is allowed to 'draw air through the inlets |33 and through the openings |40 to cool the friction faces of the rotor discs as they pass over the openings |40 `through which the air current is passing. The heated air under the centrifugal force exerted by therotating member of the brake passes into a chamber |4l adjacent the brake drum and is admitted from this chamberv to the exterior of the Wheel and brake assembly. Thus it will be seen that I have provided a system for cooling the friction members of a disc brake by means of a current of air whose move. ment is induced by the centrifugal force of the rotating members of the brake. l

It is obvious that certain of the features of my braking device may be used in other instances than the specific embodiments shown. It is therefore my intention not to limit my invention to the specific embodiments shown or to limit the said invention in any way other than the terms of the appended claims I claim:

1. A disc brake comprising a rotor member, a stator member, a piston for at times moving said stator member into frictional contact with said rotor member, a cylinder in which lsaid piston is reciprocable, and a tube for moving said piston relative to said cylinder, the tube having substantially at surfaces on opposite ends and having its sides intermediate the ends normally folded inwardly toward the center of the tube when the brake is in released position, the piston and the cylinder having respectively flat surfaces engaged by the' at end surfaces of the tube and having pairs of adjacent inner and outer coaxial cylindrical surfaces, one of each pair within and the other encircling said tube and confining the inside and the periphery of the tube adjacent its I two ends, whereby' the ends of the tube are seated respectively in one end of the cylinder and in the back of the piston and the tube is confined against expansion otherwise than in an axial direction.

.2. A disc brake comprising a rotor member, a stator member, a piston for at times moving said stator member into frictional contact with said rotor member, a cylinder in which said piston is reciprocable, a tube for moving said piston relative to said cylinder, and means for admitting uid under pressure to the interior of the said tube, the tube having substantially flat surfaces on opposite end and having its sides intermediate the ends normally folded inwardly toward the center of the tube when the brake is in released position, the piston and the cylinder having respectively flat surfaces engaged bythe flat end surfaces of the tube and having pairs of adjacent inner and outer coaxial cylindrical surfaces, one of each pair within and the other encircling said tube and confining the inside and the periphery of the tube adjacent its two ends, whereby the ends of the tube are seated respectively in one end of the cylinder and in the back of the piston and the tube is confined against expansion otherwise than in an axial direction.

3. A disc brake for aircraft comprising a brake drum, one or more rotor discs associated therewith, a brake supporting member, one or more stator discs connected to the supporting member and interspersed with the rotor discs, an annular plungerfor moving the stator discs into frictional engagement with the rotor discs, and an annular chamber forming member having the plunger reciprocable therein and having threaded engagement with the brake supporting member so that it may be rotated relative to the supporting member to adjust the position of the discs after substantial wear thereof.

4. A disc brake comprising a rotor member, a stator member having a surface lined with friction material, an annular plunger for at times moving the stator member against the rotor member to impede rotation of the rotor member, said plunger having an annular recess at one side thereof, a chamber forming member having an annular chamber enclosing at least partially said annular plunger, and an expansible tube for moving the plunger relative to the chamber forming member, said tube having one end thereof conned in the. plunger recess, having the opposite end thereof confined in the walls of the chamber formed by the chamber forming member and having its sides intermediate the ends thereof folded inwardly toward the center ofthe tube, the structure and arrangement of the tube being such that during expansion to actuate the brake there is no friction between the Walls of the tube and the above described parts of the brake.

FREDERICK C. FRANK. 

